The goal of this project is to discover genes underlying taste preferences, particularly those responsible for the preferences for sodium, calcium, and acids. Over the last 15 yr, several fundamental insights into the genetic and molecular basis of taste transduction have been made using mouse models but there are disadvantages to using mice, and many questions remain. The rat has the potential to be a better model. It has traditionally been used for taste preference experiments, and there is a massive literature dealing with rat physiology, nutrition and learning mechanisms. The problem has been that until recently genetic tools for studying the rat have not been available, but this has changed. This project will take advantage of a new consomic rat resource to investigate the genetic basis of taste preferences in rats. Preliminary work has identified consomic rat strains that differ from their background strain in preferences for sodium, calcium and acids. To exploit this, we now propose to better characterize the phenotype of the consomic rat strains, and isolate the genes involved by breeding congenic rat lines. The expression patterns of genes in the congenic interval will be surveyed to evaluate their potential contribution to the phenotype. These studies will lead to the discovery and characterization of genes responsible for taste preferences.